BIO304H5 Lecture : #11 Action Potentials 3
Document Summary
Larger electric potential, sodium ions rush in, meets actiona potential. #2 must have a stornger stimulus or it can be like #3 and wait longer. If we were able to initiate a current stimulus at 2 points, one close and one far, we can determine how fast currents are conducted along that axon. With distance and time we can calculare conduction velocity. Myelinated nerves have more affect throughout the nerve, multiple channels receive stimulus. Leakiness: membrane current that leaves axon (myelin reduces leakiness therefore improving effectiveness over long distances and increasing length constant) Voltage gated channels only at nodes of ranvier. Aps generated only at the node: electrical: direct flow of electrical current from one cell to the next (hypothlamus, chemical: secrete neurotransmitter molecules that activate receptors. Most useful porperty is they are extremely fast. Electrical synapses are most found in the brain where there is synchronizing neural activity.
